SurfWatch error rate for first 1,000 .com domains

Introduction

Using "zone files" from Network Solutions (which list all .com
domains in existence), we obtained a list of the first 1,000
active ".com" domains
on the Internet as of June 14, 2000.
From this sample, we determined how many of these
sites were blocked by SurfWatch, and of those blocked sites, how many
were actually pornographic.

Of the remaining 51 sites,
42 were errors (i.e. non-pornographic sites blocked by SurfWatch
as "Sexually Explicit"), and 9
were non-errors (i.e. sexually explicit sites). This is
an error rate of 42/51 = 82%, or roughly four non-pornographic
domains blocked for every one pornographic domain blocked.

Error rate for domains: 82%

About four non-pornographic domains blocked by SurfWatch
as "Sexually Explicit", for every one
pornographic domains blocked.

NOTE: We do not block on the basis of sexual preference, nor do we block
sites regarding sexual health, breast cancer, or sexually transmitted diseases
(except in graphic examples).

However,
there were no blocked sites that we considered to be "borderline"
cases, e.g. non-pornographic black-and-white nude photography
sites. The sites in this sample were either pornographic
sites (e.g. http://a-1blowjobs.com) or completely innocuous sites
(e.g. http://a-1-dogs.com/).

We used the first 1,000 working domain names in our sample in order to make our
sample "provably random". A truly random sample chosen from the entire
list of domain names would have been better, but it would be impossible to prove
that such a sample had really been chosen randomly; a third party could easily
claim that we had "stacked the deck" by choosing a disproportionate number of
sites blocked incorrectly by SurfWatch.

Before adding any site to our database, each site 'candidate' is reviewed by a SurfWatch Content Specialist. Deciphering
the gray areas is not something that we trust to technology; it requires thought and sometimes discussion. We use
technology to help find site candidates, but rely on thoughtful analysis for the final decision.
--http://www1.surfwatch.com/about/body-filter.html

Given the high error rate for sites blocked by SurfWatch in the "Sexually Explicit"
category, we believe that SurfWatch's claim of "100% human review" is false.